WEAR-RESISTANT LINING ELEMENT AND WEAR LINING MADE THEREOF
Field of the Invention
The present invention relates to a wear-resistant lining element for a wall exposed to wear, over which piece goods or particulate goods, such as crushed ore and crushed stone material, are intended to move in a transport direction, said wear-resistant lining element having compartments which are adapted to receive the transported goods and which are upwardly open and defined by partition walls. Background Art
Wear-resistant lining elements of the type described by way of introduction are known, where the material transported along the wear-resistant lining element is used as protection against wear. Such wear-resistant lin- ing elements are used in walls that are exposed to wear in connection with transport of e.g. crushed ore, crushed stone material, coal, mineral or crusher waste.
Such wear-resistant lining elements are disclosed, for example, in GB-887,575. They are intended for tube mills and other grinding devices and have quadrilateral compartments of different dimensions. The compartments have walls and possibly bottoms made of, for instance, steel. The compartments are filled with wear material in the form of concrete or rough stone blocks . The con- crete or stone blocks are used as protection against wear caused by the stone material which is being worked in the grinding device. These prior-art wear-resistant lining elements, however, suffer from the drawback that they are worn too quickly. US-A-5, 513 , 581 discloses a chute having compartments which are filled with some of the material that is being transported in the chute, the accumulated material being
used as wear material . The compartments are made up of hard plates. By inclination of the chute, the composition of the surface protected by the wear material can be controlled. However, this is a complicated construction and does not result in the desired service life either. When the plates have become worn out, they must be exchanged each separately.
SE-421,868 discloses a mill lining of rubber or elastomeric material which includes permanent magnets. The lining is intended for mills where magnetic material, such as magnetite, is to be ground. The magnetic material is attracted by the permanent magnets and adheres to the surface of the lining, where it constitutes a renewable wear-resistant layer. This lining requires for its func- tion that magnetic material be included in the goods that are to be ground. If this is not the case, magnetic material must thus be added to obtain the renewable wear- resistant layer.
SE-509,249 discloses wear-resistant lining elements of massive elastomeric material, in which wear-resistant bodies can be integrated. These wear-resistant lining elements offer, compared with previously known wear- resistant lining elements, simplified mounting since at their lateral edges they are formed with recesses for holding connecting devices. However, it is desirable to further increase the service life of these wear-resistant lining elements. Summary of the Invention
The object of the present invention is to provide a wear-resistant lining element which is improved over prior art .
A further object of the invention is to provide a wear-resistant lining element with a long service life.
According to the invention, these objects are achieved by the wear-resistant lining element of the type mentioned by way of introduction being given the features that are evident from claim 1. Preferred embodiments of
the wear-resistant lining element are defined in the dependent claims.
The inventive wear-resistant lining element thus uses partition walls of an elastic material. Wear mate- rial in the form of fines and larger pieces of the material wearing against the wall in which the wear-resistant lining element is mounted, is accumulated in the compartments defined by the partition walls. The elasticity causes the partition walls to yield somewhat and allow gaps to be formed in and around the material accumulated in the compartments. Therefore the material in the compartments does not lie still and the impact of the transported material on the material in the compartments will thus not be of the same strength since dampening of the impact will be obtained. Also the elasticity of the partition walls results in reduced wear on the partition walls .
The partition walls are preferably made of an elastomeric material, which makes it possible to obtain a suitable degree of elasticity in an easy way.
In a preferred embodiment, the entire wear-resistant lining element is made of an elastomeric material. An elastomeric material gives the walls the appropriate elasticity and it is easy to manufacture the entire ele- ment of the same material.
The material of which the partition walls are made preferably has a hardness of 40-95 Shore A, conveniently 70-80 Shore A and most advantageously 70-75 Shore A. This gives the partition walls a suitable degree of elasti- city.
The compartments defined by the partition walls have in a plan view preferably a shape which has at least one corner in the part of the compartments which in the transport direction is the downstream part. As a result, the possibility of the partition walls to yield is improved.
According to a preferred embodiment of the invention, the compartments have an essentially square or rhombic shape which, inter alia, facilitates the manufacture of moulds for producing wear-resistant lining ele- ments .
It is advantageous if the surface exposed to wear, which is formed of the wear-resistant lining element surface provided with compartments, is wave-shaped in the transport direction of the wear goods . The wave shape causes the transported material to be transported in a "jumping motion", i.e. the material does not slide in a uniform flow along the entire surface of the wear- resistant lining elements, but will be intermittently released therefrom, which causes reduced wear on the wear-resistant lining element.
The wave shape is preferably such that upstream surface portions (impact side) of the surface provided with compartments have a steeper inclination than downstream surface portions (leeward side) . Thus the material does not fill the compartments completely and is accumulated above all in the compartments on the impact side. This provides space for the desired movability of the partition walls .
The wear-resistant lining element is advantageously designed so that at one lateral edge it has a recess and at an opposite lateral edge a projection, the recess and the projection being formed so that the recess of one wear-resistant lining element is joinable with the projection of a neighbouring wear-resistant lining element for interconnecting the wear-resistant lining elements. Owing to this design, a plurality of wear-resistant lining elements can be interconnected in a rational and safe manner to form a wear lining on a wall.
According to an embodiment of the invention, the wear-resistant lining element has recesses at two opposite lateral edges. The recesses are opened towards the
lateral edges and allow rational interconnection of a plurality of elements by means of connecting devices. Brief Description of the Drawings
The invention will now be described in more detail with reference to a preferred embodiment which is illustrated in the accompanying drawings .
Fig. 1 is a top plan view of a wear-resistant lining element according to the invention. Fig. 2 is a side view of the wear-resistant lining ele- ment in Fig. 1.
Fig. 3 is a top plan view of a number of wear-resistant lining elements according to Fig. 1. Fig. 4 is a side view of the wear-resistant lining elements in Fig. 3. Fig. 5 is a side view of four interconnected wear-resistant lining elements which are mounted on a sloping base. Description of Preferred Embodiments
The wear-resistant lining element 1 in Fig. 1 has a plurality of square compartments 2 which are defined by partition walls 3. At one lateral edge, the wear- resistant lining element 1 has a projection 4 and at an opposite lateral edge a recess 6. The projection 4 is countersunk in relation to the upper side of the wear- resistant lining element 1 but is level with the underside of the wear-resistant lining element 1. The projection 4 has at its end a first bevel 5. At the opposite lateral edge the recess 6 is formed in the underside of the wear-resistant lining element 1. A second bevel 7 is formed along the recess 6. At each of the two other lateral edges, the wear-resistant lining element 1 has recesses 10 for holding fixing elements.
The wear-resistant lining element 1 is about 300 x 340 mm and is in the shown embodiment made of poly- urethane rubber with a hardness of about 75 Shore A. Also other elastomeric materials with a suitable hardness can be used. The compartments are about 25 x 25 mm and the
thickness of the partition walls is about 5 mm. As illustrated in Fig. 2, the wear-resistant lining element 1 is wave-shaped seen in a side view. By wave shape are meant not only sine waves, but also, as in the shown embodi- ment, angled surfaces. At the crest of the wave, the compartments are about 45 mm deep and in the trough of the wave about 20 mm deep. The projection 4 is about 15 mm thick and 40 mm wide. The recess β is correspondingly 15 mm deep and also 40 mm wide. The first bevel 5 of the projection 4 is inclined outwards towards the edge of the projection 4. The second bevel 7 along the recess 6 has the same degree of inclination as the first bevel 5, but is inclined in the opposite direction. The shape of the projection 4 and the recess 6 and the bevels 5, 7 is made so that two wear-resistant lining elements can be fitted together by the projection 4 of one wear-resistant lining element 1 being tightly fitted into the recess 6 of another wear-resistant lining element, as shown in Fig. 4. Fig. 5 shows how a number of interconnected wear- resistant lining elements form a wave-shaped wear lining on a sloping base 8 , for instance the bottom of a chute for transporting crushed stone and like material. In this case the base is inclined at about 55° to the horizontal plane, but also other inclinations are possible. The fixing of the wear-resistant lining elements to the base is carried in the embodiment in the manner as described in SE-509,249 mentioned by way of introduction. The wear- resistant lining elements 1 are fixed to each other and the base 8 by means of cruciform connecting devices 9, the arms of which are inserted into the V-shaped recesses 10. The recesses 10 are formed as two chutes arranged in V form, which have their tip close to the lateral edge of the lining element 1 and which are open towards the sur- face of the wear-resistant lining element provided with compartments. The connecting device 9 in the form of cruciform washer is fixed by means of a screw 11 and a
nut 14 to the base 8. Washers 12 and 13 are arranged on the upper side of the connecting device 9 and on the underside of the base. Now the wear-resistant lining elements 1 are safely arranged relative to each other as well as to the base. Also connecting devices in some other form than in the form of a cross may be used. The form of the recesses 10 is then selected with regard to the form of the connecting devices.
A different way of allowing fixing of wear-resistant lining elements is to provide them with a metal sheet on the underside, as disclosed in SE-B-347 , 664. A wear- resistant lining element of rubber is fixed by vulcanisation to a subjacent metal sheet. Steel nails are driven from the underside of the base through an elastomeric plug, which is inserted into a hole in the base. The completed wear-resistant lining element can also be formed with through holes and be fixed to a base by means of screws or the like.
When crushed stone or like material is transported along the wear lining in a transport direction T (see Fig. 5), especially fines, but also larger pieces of stone, get stuck in the compartments 2. When material has been accumulated in the compartments 2, this functions as a wearing surface for subsequently transported material . Therefore wear takes place above all on the accumulated material and to a very small extent on the actual wear- resistant lining element 1. As the accumulator material is worn out, new wear material is supplied from the transported material . The quadrilateral compartments 2 are arranged on the wear-resistant lining element in such a manner that they have a diagonal in the flow direction T of the material. The quadrilateral form of the compartments gives the walls an improved possibility of yielding and thus reduc- ing the wear on the wear-resistant lining element. The compartments do not have to be quadrilateral, but may also have some other form, for instance five-sided, six-
sided or drop-shaped. Some corners may be rounded while one has a clear angle. The essential thing is that the compartments have a tip or a corner in the part which is the downstream part seen in the transport direction T. The elasticity of the material of which the wear- resistant lining element 1 is made causes the partition walls 3 to be yieldable to a certain extent. As a result, gaps can be formed in the wear material accumulated in the compartments, which causes the impact of the trans- ported material against the material in the compartments not to be so strong as would otherwise be the case.
The wave shape makes the transported material "jump" along the wear-resistant lining element. Thus the material does not slide all the way along the wear-resistant lining element but is made to leave the surface at some points. In this way, wear is reduced. The wave shape is designed so that the impact side of the wave, the upstream side, has a stronger inclination than the leeward side of the wave, the downstream side, which makes material accumulate above all in the compartments on the impact side. The inclination on the impact side is in this embodiment about 20° in relation to the plane underside of the wear-resistant lining element and on the leeward side about 8°. Therefore material does not fill the compartments completely and is accumulated mostly on the impact side. Since there are empty spaces in the compartments, the elasticity of the partition walls is maintained. •
In this embodiment, the entire wear-resistant lining element 1 is made of polyurethane rubber, but it is also possible to make the partition walls of one material and the bottom of the wear-resistant lining element of another material . Then the important thing is that the material of the partition walls is selected so that the desired elasticity is obtained. Preferably polymeric, rubber elastic materials are used.
In dependence on the choice of material, the wear- resistant lining element can be manufactured by moulding or by moulding and vulcanising in curing moulds.